


‘Til The Sea Itself Floweth In Your Veins

by bag_of_catZY (catZY)



Category: Captain America - All Media Types, Iron Man - All Media Types
Genre: Hydra (Marvel), M/M, Multi, Threesome - M/M/M, mermaid au
Language: English
Status: In-Progress
Published: 2017-06-01
Updated: 2017-05-31
Packaged: 2018-11-07 14:09:20
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,994
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11060613
Author URL: https://archiveofourown.org/users/catZY/pseuds/bag_of_catZY
Summary: Tony is hiding out at his private beach house after dropping the bombshell that he isn’t making any more weapons. While walking along the water, the finds an unconscious and injured man with a fish tail.Bucky is a merman who was nabbed by some crazy scientists. He has finally escaped, though unfortunately losing his arm in the process, and is so close to the sea he can taste it. But he isn’t strong enough to swim home and gets washed back onto shore, which is where Tony finds him.Steve is Bucky’s childhood friend who has been searching frantically for him ever since he’s been snatched. Will he ever get Bucky back?





	‘Til The Sea Itself Floweth In Your Veins

**Author's Note:**

  * For [MegaraNoelle](https://archiveofourown.org/users/MegaraNoelle/gifts).



> I've been on the road a lot the past two weeks, so I wasn't able to write as much as I wanted to. I've already gotten the story plotlines and character designs completely mapped out. I'll have the rest of the story up soon. Sorry!

Tony couldn’t remember the last time he’d been alone and surrounded by quiet and felt at peace instead of suffocated. The moon seemed more solid and real this far out from any city. The waves were gentle enough against the sand as to almost be a lulling susurration.

Sure, Tony knew that a whole shit show waited for him back in New York. He’d known that announcing he wasn’t going to build weapons anymore was going to make him a lot of enemies. But he was a billionaire genius—he’d always have enemies. And as clichéd as it sounded, doing the right thing made him feel lighter despite all the little minutiae he still had to work out. He’d felt bad leaving Pepper to put out his fires, but she’d insisted that getting out of the spotlight was the best he could do for the company right now. She’d told him, _let everyone cool down and then wow them with cool inventions for the company’s new direction._

And of course Pepper was right about things as usual. Even so, he still felt guilty for basically taking a vacation and doing what he loved best—inventing without bounds. He’d never felt so free and relaxed without the aid of drugs before in his life. Despite the fact that SI’s stocks were taking a dive, Tony felt like things were looking up.

It was because of this rare optimism that he had decided to take a whimsical stroll along the beach. A few years ago, he’d designed and built a little house on the beach, actually more than halfway in the water. Nobody knew about this beach house, unlike the one he had in Malibu, so he was safe from paparazzi and other unsavory characters here.

Tony stopped in his tracks when he saw a furrow of sand clumped with a liquid stickier than water. Blood. Fuck. Was he going to find a dead body? And here he had been thinking everything was all peaceful and safe here. Common sense told him he should run back to his house and call the police, but his newly awakened conscience urged him to follow the trail just in case he could save whoever was at the other end of it.

Tony started running after the trail of blood and disturbed sand with a deep-seated feeling of unease. His heart caught in his throat when he saw a dark lump about the size of a body at the water’s edge. He ran towards it with barely entertained hope. _Please don’t be a dead body, please don’t be a dead body, please don’t be a dead body._

Tony knelt in the sand by the body and released a sigh of relief when he saw faint up-and-down movement consistent with breathing. He leaned in closer to get a better look to see if the man—definitely a man, despite the long hair—was okay to move. The mystery man was unconscious, but his face—and wow that was that a good looking face, _okay Tony not the time_ —at least seemed uninjured. Tony swept the guy’s hair aside to check for neck injuries and then froze in shock. There were several long slashes—wait, fuck no, those were gills, _how did a man have gills?_

Tony scrambled back a little ways just in case this was some kind of sea monster and he was about to be eaten. But no, the body didn’t move. And now that he had a little distance, he realized that what he had mistaken for two legs pressed close together in the dark was actually a tail. A fucking tail. What was his life that he’d found an actual mermaid ( _or wait, were they called mermen if they were male_ ) while out on a casual stroll on the beach?

After he’d gotten his hammering heart mostly under control, he crept back closer to the merperson ( _there, that was good and gender neutral, Pepper would be proud_ ) to continue his rudimentary examination for injuries. After all, the blood had to have come from somewhere. When he couldn’t find anything, he gently turned the merperson over. Ah. There was the wound. Tony nearly gagged at the sight of the mangled arm—or what was left of it. Tony forced himself to turn back and take a closer look. Thank any and all deities that the wound at least didn’t look infected.

But then there was the next hurdle. What the fuck was Tony supposed to do? He couldn’t exactly call emergency services. Who knew what would happen to a guy who was a supposedly mythical creature? Tony could already imagine blank-faced men in black making this poor creature disappear into some shadowy government hellhole. He’d been selling weapons to the government for two decades; he knew what kind of snakes they could be.

But Tony couldn’t very well leave the injured merperson behind to get discovered or die of exposure. There was only one option left. Tony would have to just try to fix the injury to the best of his ability with his nonexistent medical knowledge. Tony scooped his arms underneath the merperson’s shoulders and waist as gently as he could. He tried lifting with minimal jostling, but even so, the merperson still groaned in pain. Tony froze, waiting to see if the merperson was going to wake. When he didn’t, Tony started walking slowly and steadily back home.

The merperson’s long tail flopped down onto the ground and dragged behind, but there was nothing Tony could do about that and it didn’t seem to be hurting his injured cargo so he forged onwards.

The pale, glowing moon and crashing waves seemed a lot more eerie on the trip back.

By the time Tony made it back to his little beach house, he was panting with exertion and the merperson was groaning feverishly. Tony set the merperson down slowly on the sofa with the last of his remaining strength. He collapsed back against the nearest wall to get a breather before stumble-running to the first aid kit in the bathroom.

Tony had a surprisingly extensive first aid kit for someone who didn’t actually practice medicine, but that was because he’d had too many minor workshop injuries over the years to warrant going to the hospital every time he got a little burn or cut.

While he was in the bathroom, he splashed his face with water to clear the static fogging his brain. He checked his pupils in the mirror just to be sure he wasn’t on anything and hallucinating because of it. He didn’t know whether to be relieved or disappointed to see that his pupils were even. On one hand, it was good he hadn’t taken drugs without being aware of it. On the other, that meant the fucking merperson on his couch was real.

Tony carried the first aid kit back out to his living room with a steely determination to patch up his unexpected guest and worry about all the details later. Tony had never been gladder for his steady mechanic’s hands than when he was holding up a needle and thread to the gory remains of the merperson’s left arm. The whole mess was one massive wound, but Tony figured he could stitch up the parts that were still bleeding and then bandage it all up.

After a fever dream of disinfecting, stitching, and bandaging on Tony’s part—and some pained moaning and screaming on the merperson’s part—Tony finally sat down dully on his rump and released what felt like his first full breath since his walk along the beach had come to an abrupt and grisly end.

He cleaned up the detritus of his hasty medical patch job, draped a blanket over his unwitting patient, and flopped down into the armchair facing the sofa. Between one breath and the next, he fell asleep.

 

 

 

 

Tony jerked awake to the feel of something cold and sharp pressing against his neck. He blinked several times against the bright light of day, confused about what exactly had awoken him. He froze when he realized there was a knife against his neck, and even more shockingly, the knife-wielder was the merperson he had brought back home last night.

The immediate part of his brain focused on the _very_ sharp knife against his neck—probably one of the kitchen ones he never used—and the menacing scowl on the merperson’s handsome face. A more distant part wondered how in the world someone with a fish tail instead of legs could stand up. His eyes involuntarily flicked down and then widened when he saw not a tail but two long, well-muscled legs. Well, and some other bits in between those two shapely legs ( _now was sooo not the time, Stark)_.

Shit. Had he actually dreamed up the whole merperson bit last night? But how? The knife-wielding maniac was still wearing the bandages that Tony had wrapped around the stump of his missing arm. So at least that part of last night had been real.

“Where’s your tail?” Tony asked rather dumbly.

The knife pressed against his neck harder. Tony felt his heartrate kick up another notch.

“Um, sorry, that was kind of rude. I should have introduced myself first. I’m Tony, uh, Tony Stark.” Tony almost knocked himself over the head. Why would this guy care who he was if he didn’t already know? “Never mind. Can I, um, ask why you’re holding a knife to my neck?” He wanted a hole to open up and swallow him.

The merperson—or was it just man now because of the legs—just stared at Tony blankly.

“Do you speak English? Wait, no, that’s a dumb question, if you’re a merperson, why would you know how to speak English. Not saying that merpeople can’t speak English, but just that I guess I shouldn’t expect you to, and—oh my god, just kill me now.”

Tony could have sworn the man’s full lips twitched a little into what could generously be called a smile.

“So you do understand me? Or does the Tony Stark ridiculousness transcend language? In which case, I have sunk to new lows.”

“Yes. English.” The man spoke with a rusty voice and an indeterminable accent.

“Oh, good. Well then, do you mind not menacing me with a knife? Could we just talk about whatever’s made you upset with me?”

The man seemed to think Tony wasn’t very much of a threat because after a few more tense moments, he pulled the knife away. Tony breathed a sigh of relief but didn’t relax completely because the man was still holding the knife—and yep, it was one of his never used kitchen knives. Tony needed to stop keeping a fully stocked kitchen. It was clearly hazardous to his health.

“Why bring me here?” The man asked.

“Well, I was minding my own business, taking a stroll along the water, when I found you with your arm, you know,”—here, Tony gestured to bandaged stump—“like that, and, well, I couldn’t just leave you there to bleed out, so that’s why I brought you home.”

The man considered Tony’s words before barking out, “Hydra?”

Tony blinked at him blankly. Were hydras also real?

“You Hydra?” The man demanded.

“What? No, I’m not a hydra. I’m completely human.”

The man lunged closer—god, he moved fast—and pointed the knife right at Tony’s nose, so close that Tony was going cross-eyed to keep track of it. “You scientist?”

“Sure. An engineer is a type of scientist.”

The man actually growled and _oh my god, the knife was now poking Tony in the nose_. “You experiment on me?”

“What?! Dear lord, no! I’d never experiment on people. And besides, I’m not even a scientist of the squishy sciences. I make tech”— _better not mention the weapons, just to be on the safe side_ —“like computer chips and cars and phones and renewable energy sources.”

The man stopped vibrating with murderous energy and actually drew back a little. Tony collapsed bonelessly against the back of the armchair. This was one crazy rollercoaster of a morning. And it still wasn’t over.

“Cars. Phones.” The man muttered to himself.

“Yeah,” Tony said hesitantly, “You know what those are?”

The man nodded. He flattened the hand holding the knife and made a quick motion horizontally across. “Vroom.” Then, when Tony nodded, he cradled the knife in his hand and moved his thumb across it in a poking motion as if texting. Tony nodded again.

“Yeah, I work on those. Not people.” Tony said firmly, hoping the man with the knife believed in his sincerity.

The man stared hard at Tony as if trying to peer into his soul. Tony waited with bated breath for the verdict. The man nodded and sat back down on the sofa. Tony slumped in relief.

“Can you give me back my knife?”

The man gripped the knife harder until his knuckles turned white and shook his head almost desperately.

“Okay, never mind. You keep the knife if it makes you feel better.”

They sat in somewhat awkward silence for a moment before Tony’s inability to keep quiet overcame his fear of disturbing the tentative peace between him and the stranger.

“Hey, do you want to watch a movie?”

“Movie?” The man asked, puzzled.

“It’s like—never mind, I’ll just show you.”

Tony pulled out his phone—slowly, so the man didn’t think he was pulling out a weapon—and said, “JARVIS, start _The Little Mermaid_ on the big screen.”

Tony hadn’t finished installing the equipment to allow JARVIS full control of the beach house yet, so for now, he could only contact JARVIS via networked devices like his phone.

“Of course, sir.”

The opening credits of the movie began to roll on the wide flat screen mounted on the wall opposite the sofa and arm chair. The man glared suspiciously at the phone, but when JARVIS didn’t speak again, he seemed to let it go.

When the man saw Ariel swimming around with Flounder on the screen, he snorted loudly in amusement. Tony smiled. At least the man appreciated his special brand of humor.

“Hey, what do I call you?”

The man let out some noises that sounded like a cross between whale song and dolphin clicks. Tony stared blankly at him.

The man frowned in thought before finally saying, “Bucky.”

Hmm. Bucky. Kind of odd but charming nonetheless. Tony could work with ‘Bucky’.

 

 

 

 

 

Over the next couple of days, Tony reached a new equilibrium with his houseguest. While Bucky healed up, Tony introduced him to the fine art of sandwich making and the wonders of microwave food (Bucky was especially fascinated with popcorn), the Internet, and an endless stream of movies and TV shows. Between the internet and media entertainment, Bucky’s vocabulary expanded at an exponential rate.

Bucky couldn’t read, but the speech-to-text function on his StarkTab let him search and easily take in information from various web pages. And even the not-reading thing was changing. Literacy was hard to achieve so quickly past a certain age, which led Tony to believe that merpeople must also have a written language, so Bucky was learning to read a new language versus learning to read at all.

After the first three days, Bucky stopped carrying the knife everywhere he went. After the first week, Bucky even stopped tensing up when Tony changed his bandages. Bucky was healing unusually quickly, but Tony put that down to his non-human physiology.

Tony couldn’t believe he was developing some semblance of routine because of his strange guest. He woke up in the morning to find Bucky sitting on the part of the porch that led to the sea, staring longingly into the distance. He’d make coffee for both of them. The aroma would bring Bucky inside. Then, they’d have some adventures in cooking eggs, which Tony was slowly getting better at. Or, if Tony wasn’t feeling it, they’d just eat cereal with milk. Then, they’d watch several episodes of Doctor Who before they’d get hungry for lunch. They experiment with various combinations of sandwich fixings.

Afterwards, Tony would go to his workshop to work on any of a dozen new brilliant ideas. He couldn’t remember the last time he’d been so happy to create for work rather than just for fun. He had a bunch of new program ideas to flesh out the app structure of his mobile devices. More energy efficient vehicles. Better armor for the troops—he wasn’t completely abandoning them. More cost efficient medical tech. And of course, his crown jewel, designs to miniaturize the arc reactor that could usher in a new era of clean energy once they were completed.

He’d be pulled out of the zone by the sound and smell of popcorn popping. In comparison to his other homes, his little beach house had very few rooms. Basically, just a bedroom, bathroom, living room, kitchen, workshop, and storage. And out of consideration for his guest, Tony didn’t blast his usual music very loudly. As a result, he was able to hear Bucky getting his daily popcorn fixing, which meant Bucky was hungry and it was time for dinner.

After dinner, Bucky would show Tony all the random things he had learned from the internet. And once that petered out, they would watch one of the movies on Tony’s must-see list. Then, they’d go to bed. Well, Tony would go to bed. Bucky stayed on the couch and slept there.

All this was alarmingly domestic. But Tony was surprised to find himself brimming with happiness and absolutely content to have Bucky around all the time. He had always thought that living with someone 24/7 would have been hell, but Bucky was easy to live with. More than that, Bucky was fun to live with.

Tony should have known better than to think the peace was going to last.


End file.
